1. Field of the Invention
The present invention relates to a cable broadcast program receiver and transmitter, and more particularly, to a digital cable TV receiver, a diagnosis method for the same, and a data structure of a HDMI status report, wherein the program receiver provides status information of a plurality of peripheral devices connected to the cable broadcast program receiver (or digital cable TV receiver) through a DVI link or a HDMI link.
2. Discussion of the Related Art
Generally, a Digital Visual Interface (DVI) is a transmission standard established by a consortium called the Digital Display Working Group (DDWG), which has been created by a group of leaders in the computer industry. The DVI is used to digitally connect a personal computer (PC) to a flat monitor. More specifically, the DVI is a standard for digitally connecting signals exchanged between the PC and the monitor. The DVI has mainly been adopted to peripheral devices that are used by being connected to a PC, such as personal computers, office projectors, general plasma displays, electric boards. And, recently, the DVI has also been adopted in digital television (TV) receivers and cable digital television (TV) receivers. Before the DVI standard was developed, digital signals were exchanged by a complicated process. First, the PC creates digital data. Then, even though the digital display device is capable of receiving digital data, the digital data transmitted from the PC is converted to analog data, which is converted back to digital data and then transmitted to the digital display device. Therefore, in order to avoid such a complicated process, the DVI standard has been developed to allow the digital data created from the PC to be digitally transmitted directly to the display device through a cable. In the DVI standard, digital broadcast signals that are not compressed are transmitted in a single direction.
A High-Definition Multimedia Interface (HDMI) is a transmission standard enabling digital audio and video signals to be connected by a single cable without compression. More specifically, since a multiple channel transmission (5.1 channel) can be performed in case of the audio signal, it will be more accurate to refer to the interface as a multimedia interface, rather than a video interface. In other words, the difference between the HDMI and the DVI is that the HDMI is smaller than the DVI, has a High-bandwidth Digital Content Protection (HDCP) coding functions provided therein, and supports multiple channel audio. Therefore, the HDMI standard enables the DVI to be adopted in both audio and video electronic appliances, whereas the DVI standard can adopt the DVI interface only in video electronic appliances. And so, since the HDMI is considered to be an updated version of the DVI, the related industry is beginning to renew the Input/Output interfaces applied to digital televisions (TVs) and Set-Top boxes from the DVI standard to the HDMI standard. Since the HDMI standard is an integration of the DVI-based HDCP and audio signals (EIA/CEA-861), the HDMI standard may also be referred to as DVI-HDMI. However, in order to make a clear distinction between the HDMI and the DVI in the present invention, the HDMI standard will simply be referred to as “HDMI”. Furthermore, the DVI/HDMI described in the present invention refers to “DVI and/or HDMI” and is distinguished from the term “DVI-HDMI”.
Meanwhile, a cable broadcast system broadly includes a cable broadcast station (or cable TV station) and a cable broadcast program receiver (or digital cable TV receiver). Herein, the cable broadcast station is a transmitting and receiving end transmitting cable broadcast programs, and the cable broadcast program receiver receives the transmitted cable broadcast program. The cable broadcast station may be referred to a SO head-end or a MSO head-end. The SO refers to a System Operator (SO), which is a Korean Cable System Operator (i.e., the Local Cable TV System Operator), and the MSO refers to a Multiple System Operator (MSP), which is a group of system operators.
Moreover, the cable broadcast program receiver adopts an open cable, wherein a Point of Deployment (POD) module including a Conditional Access (CA) system is separated (or detached) from the main body. For example, the POD module uses a Personal Computer Memory Card International Association (PCMCIA) card which can be mounted onto and separated from a main body slot of the cable broadcast program receiver. Therefore, the POD module may also be referred to as a cable card, and the main body, wherein the POD module is inserted, may also be referred to as a host. For example, a Digital Built-in TV or a Digital Ready TV corresponds to the host, and a combination of the host and the POD module is referred to as the cable broadcast program receiver. At this point, the host may be connected to other peripheral devices (e.g., a Digital TV, a DVD player, a digital camera/camcorder, a Set-Top box, etc.) through one of a DVI link and a HDMI link. More specifically, one or more DVI ports or HDMI ports may exist within the host. Accordingly, a plurality of peripheral devices may be connected to the host through a DVI link or a HDMI link.
Meanwhile, in the open cable standard, wherein the POD module is separated from the main body, a diagnostic function is provided to allow each status of the host to be monitored. The diagnostic function checks various statuses, such as operation status of the host and connection status of the peripheral devices. For example, in the STCE 28 2004 standard, the Generic Diagnostic Protocol is defined in a host-POD interface resource layer. The Generic Diagnostic Protocol has been defined to enable each status information of the host to be monitored in real-time through local broadcast stations (local, user) or cable broadcast stations (remote, MSO head-end). Herein, the Generic Diagnostic Protocol defines the following diagnostics shown in Table 1 below:
TABLE 1Diagnostic IDDiagnostic00Set-Top memory allocation01Software version02Firmware version03MAC status04FAT status05FDC status06Current Channel Report071394 Port08DVI status09~FFReserved for future use
More specifically, when a request for diagnostic is transmitted to the host from the POD module, and when the Diagnostic ID is ‘08’, the details of the request consist of verifying the DVI status of the host and reporting the verified DVI status to the POD module.
FIG. 1 illustrates an example of a Diagnostic Confirm Object Syntax through which the host verifies a DVI status and transmits a report to the POD module. More specifically, the POD module parses a Diagnostic_cnf APDU (i.e., a Diagnostic Confirm Object Syntax) transmitted from the host and parses a report syntax corresponding to each Diagnostic ID, thereby extracting the status information for each diagnostic item. For example, in the Diagnostic Confirm Object Syntax of FIG. 1, when the parsed Diagnostic ID is ‘0x08’, then a DVI Status Report Syntax is parsed, thereby extracting the DVI status information. In other words, when the POD module transmits a diagnostic request (Diagnostic_req APDU) to the host requesting the host to verify the DVI status and to report the verified back to the POD module, the host checks the DVI status and transmits the result back to the POD module in the form of a DVI Status Report Syntax (Diagnostic_cnf APDU). Therefore, according to the Generic Diagnostic Protocol shown in FIG. 1, the POD module cannot request a HDMI status information from the host, and the host cannot provide any HDMI status information to the POD module.